Saving the black-footed ferret

Area biologist joins effort to restore a species

Courtesy PhotosTwo kits, or a mom ferret and her kit, are housed at the breeding facility.

Back in 2001, Colorado became home to the largest captive population of black-footed ferrets, one of the most endangered mammals in North America. In November, Pam Martin, an educator at the Kansas Wetlands Education Center, visited the National Black-Footed Ferret Conservation Center in Carr, Colo.
The story of the black-footed ferret is fascinating, Martin said. The species was not discovered until the 1800s, and in the 20th century it was thought to be extinct.
Then, in 1981, a ranch dog brought one of the animals to its owner, who showed it to a biologist. A search turned up 17 ferrets near Meeteetse, Wyoming. More were found but some died of distemper.
Three male biologists worked “80 miles from anywhere” capturing the ferrets and stitching each other up whenever they were bitten, Martin said.
Eventually 18 animals were captured. The biologists wrote a breeding chart on a large piece of Christmas wrapping paper. That historic record is now at the Smithsonian.
“The breeding program has been very successful,” Martin said. A captive breeding program began in 1986, and from the 18 original captives, one remarkable female, named Mom, had 21 kits.
The Wyoming Game and Fish Department, in partnership with the U.S. Fish and Wildlife Service and the owners of two ranches, soon released 35 black-footed ferrets outside Meeteetse, Wyoming.
Today, captive bred ferrets have been released throughout western North America, including sites in western Kansas.
Martin met Kimberly Fraser, the director of the Colorado center, at a conference and scheduled a visit. No one is allowed to tour the facility during breeding season, but at the appropriate time she arrived and got the grand tour.
The ferrets sold in pet stores are a domesticated version of a European breed. The North American black-footed ferret is a fierce, nocturnal hunter that attacks sleeping prairie dogs.

There are 11 staff members at the breeding facility, including biologists, technicians and the education director. Release pens, pictured here, are the last stop before release. The ferret must catch and kill a prairie dog before it can be released. People are kept away from the pens so the ferrets remain as wild as possible.

“They look like little vampires,” Martin said, noting they have the longest canine per body ratio of any carnivore.
Wild ferrets are totally dependent upon prairie dog burrows for cover and upon prairie dogs and other small mammals for food. According to the Kansas Department of Wildlife, Parks and Tourism, black-footed ferrets once ranged over approximately the western 2/3 of Kansas in association with black-tailed prairie dogs. Extensive conversion of rangeland to cropland plus widespread poisoning of prairie dogs have destroyed most of the state’s ferret habitat.
The ferrets and prairie dogs they depend on for food are also susceptible to distemper and plague, Martin said. “Prairie dogs are what we call a keystone species.” They engineer and make habitat, and eight or nine other species depend on them. “As the prairie dog population has been decimated, so too have these other animals.”

The breeding chart is the a copy of the original, first breeding chart of the 17 ferrets captured. One more was captured and added the next year for a total of 18. The original chart is at the Smithsonian. You can see “Mom” was quite successful!

While the breeding programs have been successful, there’s still a genetic bottleneck due to the small number ferrets from the original program. “You lose genetic variation,” Martin said. “They’re in a hard place, but as Kimberly (Fraser) said, you have to have hope.”
At the Colorado site, hundreds of ferrets are born every year and receive vaccinations against plague and canine distemper. From the breeding rooms, they are moved to pens and raised with minimum human contact. Once a ferret has killed its first prairie dog, it can be released into the wild, although some end up at zoos and nature centers.
As of December 2015, there were about 300 black-footed ferrets alive in the wild. Then, biologists started putting vaccine in peanut butter, which is then smeared on M&M candies and scattered across their habitat. In 2016, Newsweek magazine reported that scientists developed a device that was basically “a glorified gumball machine” and used a drone to shoot the vaccine-covered candies over a wider area.